BDNF and brain ischemia: Brain-derived neurotrophic factor (BDNF) can inhibit apoptosis by regulating the expression of Bal-2 and Bax proteins, etc. PNS can promote the expression of BDNF, which enhances the endogenous repair mechanism after cerebral ischemia, and helps to improve the neurological deficits in rats, reduce the scope of cerebral infarction, and reduce neuronal apoptosis.